We present searches for gas–phase CO2 features in the ISO–SWS infrared spectra of four deeply embedded massive young stars, which all show strong solid CO2 absorption. The abundance of gas–phase CO2 is at most 2: 10 7 with respect to H2, and is less than 5% of that in the solid phase. This is in strong contrast to CO, which is a factor of 10–100 more abundant in the gas than in solid form in th...

We present searches for gas–phase CO2 features in the ISO–SWS infrared spectra of four deeply embedded massive young stars, which all show strong solid CO2 absorption. The abundance of gas–phase CO2 is at most 2: 10 7 with respect to H2, and is less than 5% of that in the solid phase. This is in strong contrast to CO, which is a factor of 10–100 more abundant in the gas than in solid form in th...

Modulating the interaction between small gas molecules and solid host materials is becoming increasingly important for the future society due to the alternative energy resources especially for the hydrogen energy. As is known, two catalogues of materials such as two-dimensional (2D) lamellar cavity structures and three-dimensional (3D) infinite tunnel structures have received intensive consider...

We present a simulation framework to integrate several aspects of the combustion and burning process in a unified and modular manner. A simple three gas flame model is used to simulate a combustion process, while air motion is simulated as a single moving fluid. Solid objects inside the simulation domain can catch fire and start burning. Heat information is transferred from the fluid simulator ...

We propose a two-dimensional problem involving fluid-solid coupling where a solution is given in closed form. The upper half of the domain is modeled as an isotropic solid; the lower part as a compressible gas. The loading of the solid at the fluid-solid boundary is called superseismic when its speed is larger than the speed of propagation of disturbances in the bulk of the material. The loadin...

Discrete particle simulations are by now well established as an effective tool to study the mechanics of complex gas-solid flows in gas-fluidized beds. In this study, a state-of-the-art discrete particle model is used to explore the role of particle-particle interactions in bubbling gas-fluidized beds of Geldart A particles. We find that the particle-particle interactions, including inelastic p...